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US5286684A Expired / Lapsed US ⏱️ 0.0 years remaining

Aluminum oxide-based sintered object and process for producing the same

Assignee: Niterra Co Ltd
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Filing: 1993-02-10
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Granted: 1994-02-15
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Expires: 2013-02-10
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Abstract

Abstract An aluminum oxide-based sintered object having excellent abrasion resistance includes α-aluminum oxide, a silicon compound and a tungsten compound, wherein the silicon compound and the tungsten compound are present in amounts based on starting amounts of SiC and W metal of from 5 to 40 mole % and from 0.5 to 25 mole %, respectively, based on the sintered object overall, with a W/SiC molar ratio of 4 or less, and in which particles of at least one of tungsten carbide and tungsten silicide having an average particle diameter of 0.5 μm or less are dispersed as a crystalline phase.

Inventors

  • 👤 Jun Otsuka
  • 👤 Satoshi Iio
  • 👤 Yo Tajima

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 05:31
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/117; C04B35/622; C04B35/64; C04B35/645; C04B35/6455

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 105 words
An aluminum oxide-based sintered object having excellent abrasion resistance which comprises α-aluminum oxide, a silicon compound and a tungsten compound, wherein the silicon compound and the tungsten compound are present in amounts based on starting amounts of SiC and W metal of from about 5 to about 40 mole % and from about 0.5 to about 25 mole %, respectively, based on the sintered object overall, with a W/SiC molar ratio of 4 or less, and in which particles of at least one of tungsten carbide and tungsten silicide having an average particle diameter of 0.5 μm or less are dispersed as a crystalline phase.
Claim 2
Dependent Claim 105 words
An aluminum oxide-based sintered object having excellent abrasion resistance which comprises α-aluminum oxide, a silicon compound and a tungsten compound, wherein the silicon compound and the tungsten compound are present in amounts based on starting amounts of SiC and W metal of from about 5 to about 40 mole % and from about 0.5 to about 25 mole %, respectively, based on the sintered object overall, with a W/SiC molar ratio of 4 or less, and in which particles of at least one of tungsten carbide and tungsten silicide having an average particle diameter of 0.5 μm or less are dispersed as a crystalline phase.
Claim 3
Dependent Claim 18 words
An aluminum oxide-based sintered object as in claim 1, wherein a silicon-containing glass is present at grain boundaries.
Claim 4
Dependent Claim 35 words
An aluminum oxide-based sintered object as in claim 1, wherein the amount of silicon carbide is 7 to 40 mole % as based on SiC and the molar ratio of W/SiC is 2 or less.
Claim 5
Dependent Claim 25 words
An aluminum oxide-based sintered object as in claim 3, wherein the amount of silicon carbide is 10 to 40 mole % as based on SiC.
Claim 6
Dependent Claim 128 words
A process for producing an aluminum oxide-based sintered object which comprises (1) mixing powders of silicon carbide, SiC, in an amount of from about 5 to about 40 mole %, tungsten, W, in an amount of from about 0.5 to about 25 mole %, and an α-Al 2 O 3 source constituting the remainder, each of the amounts of SiC and W being based on the sum of the SiC amount, the W amount, and the α-Al 2 O 3 source amount determined in terms of α-Al 2 O 3 , and the SiC and W being present in a W/SiC molar ratio of 4 or less, and (2) then sintering the mixture in a non-oxidizing atmosphere at a temperature of from about 1,500° to about 1,900° C.
Claim 7
Dependent Claim 128 words
A process for producing an aluminum oxide-based sintered object which comprises (1) mixing powders of silicon carbide, SiC, in an amount of from about 5 to about 40 mole %, tungsten, W, in an amount of from about 0.5 to about 25 mole %, and an α-Al 2 O 3 source constituting the remainder, each of the amounts of SiC and W being based on the sum of the SiC amount, the W amount, and the α-Al 2 O 3 source amount determined in terms of α-Al 2 O 3 , and the SiC and W being present in a W/SiC molar ratio of 4 or less, and (2) then sintering the mixture in a non-oxidizing atmosphere at a temperature of from about 1,500° to about 1,900° C.
Claim 8
Dependent Claim 32 words
A process for producing an aluminum oxide-based sintered object as in claim 5, wherein the process further comprises subjecting the sinter resulting from the sintering step to a hot isostatic pressure treatment.
Claim 9
Dependent Claim 39 words
A process for producing an aluminum oxide-based sintered object as in claim 5, wherein the amount of silicon carbide is 7 to 40 mole % as based on SiC and the molar ratio of W/SiC is 2 or less.
Claim 10
Dependent Claim 29 words
A process for producing an aluminum oxide-based sintered object as in claim 7, wherein the amount of silicon carbide is 10 to 40 mole % as based on SiC.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-02-14 1997-08-16 1998-02-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-02-14 2001-08-16 2002-02-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-02-14 2005-08-16 2006-02-15 $7700.00 Window Closed / Lapsed

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